Image forming apparatus, toner density control method, toner density control program and storage medium for storing the program

Abstract

An amount of toner consumption accompanying development of an image corresponding to the image data is calculated based on image data, and a corrected consumption amount is calculated by multiplying the calculated amount of toner consumption by a predetermined correction ratio that is less than 1. Further, toner is supplied based on the calculated corrected consumption amount. As a result, it is possible to prevent excessive supply of toner, and to supply toner without time delay.

1. An image forming apparatus for developing, on a recording medium, an image corresponding to image data, by use of two-component developer constituted of toner and carrier, said image forming apparatus comprising:
 a developing chamber for containing the two-component developer used for development of the image; 
 a supply member for supplying toner to the developing chamber; 
 a toner consumption amount calculation section for calculating, based on the image data, an amount of toner consumption accompanying the development of the image corresponding to the image data; 
 a corrected consumption amount calculation section for calculating a corrected consumption amount by multiplying the calculated amount of toner consumption by a predetermined correction ratio that is less than 1, so that the corrected consumption amount is always smaller than the actual toner consumption; and 
 a toner density control section for causing the supply member to perform main supply in which toner is supplied to the developing chamber based on the calculated corrected consumption amount and for controlling toner density of the two-component developer contained in the developing chamber. 
 
   
   
     2. The image forming apparatus as set forth in  claim 1 , wherein the toner density control section performs main supply of toner based on the corrected consumption amount when toner unused for the development and remaining on a position of the development is conveyed via a predetermined route to a vicinity of a place where the supply member supplies toner in developing the image corresponding to the image data used for the calculation of the corrected consumption amount. 
   
   
     3. The image forming apparatus as set forth in  claim 1 , wherein:
 the toner consumption amount calculation section calculates a toner consumption ratio that is a toner consumption amount per unit time, and 
 the corrected consumption amount calculation section calculates a corrected consumption ratio by multiplying the toner consumption ratio by a predetermined correction ratio that is less than 1, and the corrected consumption amount calculation section calculates a corrected consumption amount per a predetermined time by integrating the corrected consumption ratio. 
 
   
   
     4. The image forming apparatus as set forth in  claim 1 , wherein the toner density control section intermittently operates the supply member according to an amount of toner to be supplied. 
   
   
     5. An image forming apparatus for developing, on a recording medium, an image corresponding to image data, by use of two-component developer constituted of toner and carrier, said image forming apparatus comprising:
 a developing chamber for containing the two-component developer used for development of the image; 
 a supply member for supplying toner to the developing chamber; 
 a toner consumption amount calculation section for calculating, based on the image data, an amount of toner consumption accompanying the development of the image corresponding to the image data; 
 a corrected consumption amount calculation section for calculating a corrected consumption amount by multiplying the calculated amount of toner consumption by a predetermined correction ratio that is less than 1; 
 a toner density control section for causing the supply member to perform main supply in which toner is supplied to the developing chamber based on the calculated corrected consumption amount and for controlling toner density of the two-component developer contained in the developing chamber; and 
 a toner density detection section for detecting the toner density in the developing chamber by use of a toner density sensor, wherein the toner density control section subtracts, from an amount of toner to be contained in the developing chamber so as to adjust the toner density in the developing chamber to be a targeted value, (i) an amount of toner contained in the developing chamber calculated based on the toner density detected by the toner density detection section and (ii) an amount of toner to be supplied to the developing chamber based on the corrected consumption amount, and the toner density control section causes the supply member to perform subsidiary supply in which toner whose amount corresponds to a result of the subtraction is supplied to the developing chamber. 
 
   
   
     6. The image forming apparatus as set forth in  claim 5 , wherein the toner density control section calculates an amount of toner to be supplied in the subsidiary supply based on (i) the corrected consumption amount and (ii) toner density detected when toner unused for the development and remaining on a position of the development is conveyed to a density detection region of the toner density sensor via a predetermined route in developing the image corresponding to the image data used for the calculation of the corrected consumption amount. 
   
   
     7. A toner density control method for controlling toner density of two-component developer, constituted of toner and carrier, which is contained in a developing chamber included in an image forming apparatus for developing, on a recording medium, an image corresponding to image data, by use of the two-component developer, said toner density control method comprising:
 a toner consumption amount calculation step for calculating, based on the image data, an amount of toner consumption accompanying development of the image corresponding to the image data; 
 a corrected consumption amount calculation step for calculating a corrected consumption amount by multiplying the calculated amount of toner consumption by a predetermined correction ratio that is less than 1, so that the corrected consumption amount is always smaller than the actual toner consumption; and 
 a main supply step for supplying toner to the developing chamber based on the calculated corrected consumption amount. 
 
   
   
     8. The method as set forth in  claim 7 , wherein in the main supply step, main supply of toner is performed based on the corrected consumption amount when toner unused for the development and remaining on a position of the development is conveyed to a vicinity of a place where toner is supplied in developing the image corresponding to the image data used for the calculation of the corrected consumption amount. 
   
   
     9. The method as set forth in  claim 7 , wherein:
 a toner consumption ratio that is a toner consumption amount per unit time is calculated in the toner consumption amount calculation step, and 
 a corrected consumption ratio is calculated by multiplying the toner consumption ratio by a predetermined correction ratio that is less than 1 and a corrected consumption amount per a predetermined time is calculated by integrating the corrected consumption ratio in the corrected consumption amount calculation step. 
 
   
   
     10. The method as set forth in  claim 7 , wherein in the main supply step and/or the subsidiary supply step, a supply member that is included in the image forming apparatus and supplies toner to the developing chamber is intermittently operated according to an amount of toner to be supplied. 
   
   
     11. A toner density control method for controlling toner density of two-component developer, constituted of toner and carrier, which is contained in a developing chamber included in an image forming apparatus for developing, on a recording medium, an image corresponding to image data, by use of the two-component developer, said toner density control method comprising:
 a toner consumption amount calculation step for calculating, based on the image data, an amount of toner consumption accompanying development of the image corresponding to the image data; 
 a corrected consumption amount calculation step for calculating a corrected consumption amount by multiplying the calculated amount of toner consumption by a predetermined correction ratio that is less than 1; 
 a main supply step for supplying toner to the developing chamber based on the calculated corrected consumption amount; 
 a toner density detection step for detecting toner density in the developing chamber by use of a toner density sensor; and 
 a subsidiary supply step for subtracting, from an amount of toner to be contained in the developing chamber so as to adjust the toner density in the developing chamber to be a targeted value, (i) an amount of toner contained in the developing chamber calculated based on the toner density detected by the toner density detection step and (ii) an amount of toner to be supplied based on the corrected consumption amount, so as to supply toner whose amount corresponds to a result of the subtraction to the developing chamber. 
 
   
   
     12. The method as set forth in  claim 11 , wherein in the subsidiary supply step, an amount of toner to be supplied in the subsidiary supply is calculated based on (i) the corrected consumption amount and (ii) toner density detected when toner unused for the development and remaining on a position of the development is conveyed to a density detection region of the toner density sensor via a predetermined route in developing the image corresponding to the image data used for the calculation of the corrected consumption amount. 
   
   
     13. A computer-readable storage medium, storing a toner density control program for causing a computer to carry out a toner density control method for controlling toner density of two-component developer, constituted of toner and carrier, which is contained in a developing chamber included in an image forming apparatus for developing, on a recording medium, an image corresponding to image data, by use of the two-component developer, wherein the toner density control method comprises:
 a toner consumption amount calculation step for calculating, based on the image data, an amount of toner consumption accompanying development of the image corresponding to the image data; 
 a corrected consumption amount calculation step for calculating a corrected consumption amount by multiplying the calculated amount of toner consumption by a predetermined correction ratio that is less than 1, so that the corrected consumption amount is always smaller than the actual toner consumptions; and 
 a main supply step for supplying toner to the developing chamber based on the calculated corrected consumption amount.